The invention concerns a filter element as well as a fluid filter with a radial vent hole.
For filtering fluids, such as in particular fuels, fluid filters are employed in practice whose filter elements in general comprise an annularly arranged filter medium that is held between two end discs. The filter medium can be embodied in particular as a star-shaped folded bellows and can be comprised of a nonwoven or another textile material, for example.
The function of the fluid filter or of the filter element can be significantly disturbed by the introduction of a larger gas volume or air volume into the fluid filter. The filter medium often constitutes an unsurmountable barrier for passage of the introduced gas volume or air volume so that the introduced gas volume or air volume collects fluidically upstream of the filter medium of the filter element, i.e., at the so-called raw fluid side. Due to the compressibility or expansion capability of the introduced gas or of the introduced air, flow-through disturbances and, in an extreme case, a complete interruption of the fluid column may occur within the fluid filter. This is in particular a disadvantage in case of critical applications such as, for example, in fuel filtration for internal combustion engines.
WO 2007/010037 A1 discloses a fuel filter which is provided with a venting unit. The venting unit comprises a flow passage through which gases that collect within an end face area of the filter housing can be discharged. The flow passage extends in axial direction through an end disc at an end face of the filter element and connects a raw fluid side of the filter element with its clean fluid side. In operation, it is possible in this way that air or gas introduced into the fluid filter can pass to the clean fluid side by bypassing the filter medium and be guided out of the filter element together with the filtered fuel. The flow passage is covered at the inlet side by a screen body or filter body that is fastened to the filter element by means of a holding ring that is clipped onto the end disc.
In tight mounting situations, for example, in so-called (fuel) disposable filters in which the filter housing is exchanged together with the filter element arranged therein, the known filter element is usable only to a limited extent as a result of the required mounting space. Moreover, the filter element is producible only in a complex way and therefore is cost-intensive with regard to manufacture.
Object of the invention is to provide a filter element as well as a fluid filter that enable venting and that require only a minimal mounting space while having a simple constructive configuration.